U.S. patent application number 12/498593 was filed with the patent office on 2010-01-14 for access mechanisms for base stations in heterogeneous access point networks.
This patent application is currently assigned to QUALCOMM Incorporated. Invention is credited to Avneesh Agrawal, Naga Bhushan, Mohammad J. Borran, Aamod D. Khandekar.
Application Number | 20100008230 12/498593 |
Document ID | / |
Family ID | 41505065 |
Filed Date | 2010-01-14 |
United States Patent
Application |
20100008230 |
Kind Code |
A1 |
Khandekar; Aamod D. ; et
al. |
January 14, 2010 |
ACCESS MECHANISMS FOR BASE STATIONS IN HETEROGENEOUS ACCESS POINT
NETWORKS
Abstract
Providing for improved access communication for wireless systems
is described herein. By way of example, wireless devices can employ
wireless resource re-use in selecting a subset of access
communication resources, to mitigate interference on uplink access
requests. Re-use can be based on current network conditions, or on
a type of base station facilitating the wireless communication. In
some aspects, planned resource re-use can be facilitated by an
access terminal. The access terminal requests neighboring or
interfering network access points to reserve a set of resources for
a serving access point. Reserved resources can be conveyed to the
serving access point with an uplink access probe, to further
mitigate interference.
Inventors: |
Khandekar; Aamod D.; (San
Diego, CA) ; Agrawal; Avneesh; (San Diego, CA)
; Borran; Mohammad J.; (San Diego, CA) ; Bhushan;
Naga; (San Diego, CA) |
Correspondence
Address: |
QUALCOMM INCORPORATED
5775 MOREHOUSE DR.
SAN DIEGO
CA
92121
US
|
Assignee: |
QUALCOMM Incorporated
San Diego
CA
|
Family ID: |
41505065 |
Appl. No.: |
12/498593 |
Filed: |
July 7, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61080045 |
Jul 11, 2008 |
|
|
|
Current U.S.
Class: |
370/237 ;
370/311; 370/329 |
Current CPC
Class: |
H04W 72/02 20130101;
H04W 48/12 20130101; H04W 72/082 20130101; H04W 16/10 20130101;
H04W 48/20 20130101; H04W 72/0406 20130101 |
Class at
Publication: |
370/237 ;
370/311; 370/329 |
International
Class: |
H04W 48/02 20090101
H04W048/02; G08C 17/02 20060101 G08C017/02; H04L 1/24 20060101
H04L001/24 |
Claims
1. A method of facilitating access to a wireless communication
environment comprising diverse types of wireless access points,
comprising: employing a processor to parse a set of wireless
resources dedicated for access communication and employ a re-use
algorithm to generate a subset of the wireless resources reserved
for a particular network access point if interference at the access
point is above a minimum threshold; and outputting the generated
subset to a wireless transmitter for broadcast transmission to
facilitate terminal access to the particular network access
point.
2. The method of claim 1, further comprising: receiving a network
access request on the subset of the wireless resources; and
extracting information from the access request indicative of at
least one downlink (DL) wireless resource reserved for the
particular network access point by an access point neighboring or
causing interference to the particular access point.
3. The method of claim 2, further comprising employing the reserved
DL wireless resource to transmit an access grant in response to the
access request.
4. The method of claim 1, wherein generating the subset of the
wireless resources further comprises selecting a sub-band or
sub-slot of a wireless signal based at least in part on a measure
of channel interference or network load.
5. The method of claim 1, wherein generating the subset of the
wireless resources further comprises selecting a common time
segment specified for network access points within a macro coverage
area if network load within the coverage area is below a threshold
level.
6. The method of claim 1, wherein generating the subset of the
wireless resources further comprises random selection of a time
sub-slot or frequency sub-band of the set of wireless
resources.
7. The method of claim 1, wherein generating the subset of the
wireless resources further comprises negotiating with a neighboring
or interfering access point to secure the subset for the particular
access point for a limited time.
8. The method of claim 7, wherein negotiating is based at least on
quality of service (QoS) commitments of the particular network
access point.
9. The method of claim 1, further comprising: determining an access
type or transmit power type of the particular access point; and
generating the subset of the wireless resources based at least in
part on the access or transmit power type.
10. The method of claim 1, further comprising: obtaining network
load for the wireless communication environment relative a set of
load thresholds; and dynamically selecting the re-use algorithm
based on UL or DL interference on the set of resources.
11. The method of claim 10, further comprising: selecting a natural
re-use algorithm if the current network load is below a minimum
load threshold; selecting a random or pseudo-random re-use
algorithm if the current network load is above the minimum load
threshold and below a maximum threshold; and selecting a planned
re-use algorithm and negotiation scheme if the if the current
network load is above the maximum threshold.
12. An apparatus that facilitates communication with a network,
comprising: memory that includes stored protocols that identify
wireless signal resources for network access communication
involving the apparatus; a wireless transmitter for broadcasting a
subset of wireless resources employed for access communication with
the apparatus; and a data processor that executes the following
modules: a re-use module that establishes a re-use scheme for
access resource selection based at least on network load or
interference conditions; a selection module that employs the re-use
scheme to generate the subset of wireless resources from a set of
network access resources.
13. The apparatus of claim 12, further comprising an interface
module that obtains a measurement of the network load conditions
from a high layer component of the network.
14. The apparatus of claim 12, wherein the selection module
compares the network load conditions with a set of load thresholds
to establish the re-use scheme.
15. The apparatus of claim 14, wherein at least one of: the
selection module employs a natural re-use scheme if the network
load measurement is below a minimum threshold; the selection module
employs a random re-use scheme if the network load measurement is
below an upper threshold and above a minimum threshold; or the
selection module employs a planned re-use scheme if the network
load measurement is above an upper threshold.
16. The apparatus of claim 12, further comprising a negotiation
module that manages communication between the apparatus and a
neighboring or interfering network access point to reduce
interference on the subset of wireless resources if the re-use
scheme is a planned re-use scheme.
17. The apparatus of claim 16, wherein the negotiation module
requests the network access point to blank or employ reduced power
on the subset of wireless resources.
18. The apparatus of claim 16, wherein the negotiation module
conveys the request via a wired or wireless backhaul between the
apparatus and the network access point.
19. The apparatus of claim 16, wherein the negotiation module
obtains an over-the-air (OTA) message from an access terminal that
specifies resources reserved by the network access point for the
apparatus.
20. The apparatus of claim 12, further comprising a classification
module that selects the set of network access resources from a
superset of access resources based on a transmit power type or
access type of the apparatus.
21. The apparatus of claim 12, further comprising a dynamic
resource module that monitors changes in subsequent load or
interference conditions and updates the re-use module with current
conditions.
22. The apparatus of claim 21, wherein the re-use module changes
the re-use scheme and the selection module generates a new subset
of wireless resources based on the current conditions.
23. An apparatus for wireless communication, comprising: means for
employing a processor to obtain a set of wireless resources
employed for access communication with a particular network access
point; means for employing the processor to modify the set of
wireless resources based on changes in network load or interference
conditions; and means for employing a wireless transmitter to
broadcast the set of wireless resources to facilitate terminal
access to the particular network access point.
24. At least one processor configured for wireless communication,
comprising: a first module that parses a set of wireless resources
dedicated for access communication; a second module that employs a
re-use algorithm to generate a subset of the wireless resources
reserved at least for a particular network access point; and a
third module that outputs the generated subset for broadcast
transmission to facilitate terminal access to the particular
network access point.
25. A computer program product, comprising: a computer-readable
medium, comprising: a set of codes for causing a computer to parse
a set of wireless resources dedicated for access communication; an
additional set of codes for causing the computer to employ a re-use
algorithm to generate a subset of the wireless resources reserved
at least for a particular network access point; and a further set
of codes for causing the computer to output the generated subset
for broadcast transmission to facilitate terminal access to the
particular network access point.
26. A method of accessing a wireless network, comprising: employing
a wireless receiver to obtain a set of wireless signal access
resources employed by a wireless network access point; employing a
data processor to select a subset of the wireless signal access
resources for transmission of an access probe to the wireless
network, wherein the selected subset are reserved by a second
wireless network access point; and employing a wireless transmitter
to deliver the access probe to the wireless network access
point.
27. The method of claim 26, wherein selecting the subset further
comprises selecting a subset of signal access resources employed by
a particular type of access point.
28. The method of claim 27, wherein the particular type of access
point is a restricted association access point or a low power
access point.
29. The method of claim 26, wherein selecting the subset further
comprises employing a random function to select a time-frequency
segment of the access resources.
30. The method of claim 26, further comprising specifying DL
resources reserved by the second wireless network access point in
the access probe.
31. The method of claim 26, further comprising obtaining an
indication of DL interference at the wireless receiver and
selecting the subset to mitigate the interference.
32. The method of claim 26, further comprising requesting an
interfering access point to reduce power or blank signal resources
on the selected subset of resources, wherein selection of the
subset results from the interfering access point responding in
agreement to the request.
33. The method of claim 32, further comprising forwarding the
agreement to the request to the wireless network access point and
obtaining a response from such access point indicating resources to
select for the subset.
34. The method of claim 26, further comprising receiving an
indication of current network load from the wireless network access
point for selection of the subset.
35. The method of claim 34, further comprising employing a resource
re-use scheme for selection of the subset based at least in part on
the current network load.
36. The method of claim 35, further comprising employing a natural
re-use scheme, random re-use scheme or planned re-use scheme for
the resource re-use scheme, wherein the re-use scheme provides a
distinct manner for selection of the subset of resources.
37. An apparatus for wireless communication, comprising: a wireless
transceiver for sending and receiving wireless signals; memory that
stores network protocols for identifying access channels employed
by network access points; and a data processor configured to
execute the following modules: a preference module that monitors
received DL signals and identifies a preferred network access point
from the signals; an access module that employs the stored
protocols to obtain access communication resources reserved by a
non-preferred network access point for the preferred network access
point; a signaling module that generates an access probe to be
transmitted by the wireless transceiver over the reserved
resources.
38. The apparatus of claim 37, wherein the access module references
the network protocols stored in memory to obtain the specified
resources.
39. The apparatus of claim 37, wherein the access module analyzes a
transmission from the preferred network access point identifying
the specified resources.
40. The apparatus of claim 37, wherein the access module analyzes a
transmission received from the non-preferred network access point
identifying the specified resources.
41. The apparatus of claim 37, further comprising a measurement
module that calculates interference on access channels employed by
the network access points, wherein the specified resources are
referenced at least in part based on the calculated
interference.
42. The apparatus of claim 37, further comprising a mediation
module that requests the non-preferred access point to reduce
transmit power on the specified resources employed by the preferred
network access point.
43. The apparatus of claim 42, wherein a response to the transmit
power reduction request is conveyed to the preferred network access
point to select DL access resources.
44. The apparatus of claim 43, wherein: the wireless transceiver
obtains a DL resource selection as a result of conveying the
response to the transmit power reduction request; and the wireless
transceiver tunes to the selected DL resource to obtain an access
grant/denial.
45. The apparatus of claim 37, wherein the stored protocols include
a re-use protocol specifying particular access channel resources to
be employed based on network load or interference conditions.
46. The apparatus of claim 45, wherein the re-use protocol
instructs the access module to at least one of: employ a common
segment of an access channel for low network interference or load;
employ a random or pseudo-random algorithm to select a subset of
access channel resources for moderate network interference or load;
or request the preferred network access point to identify access
resources based on negotiations with neighboring access points for
high interference or load.
47. The apparatus of claim 46, wherein the apparatus provides OTA
communication with the non-preferred access point to facilitate the
negotiations.
48. An apparatus for accessing a wireless network, comprising:
means for employing a wireless receiver to obtain a set of wireless
signal access resources employed by a wireless network access
point; means for employing a data processor to negotiate with a
neighboring or interfering access point for reserved resources for
access communication involving the wireless network access point;
and means for employing a wireless transmitter to deliver the
access probe and reserved resources to the wireless network access
point.
49. At least one processor configured for wireless communication,
comprising: a first module that obtains a set of wireless signal
access resources employed by a wireless network access point; a
second module that negotiates with a neighboring or interfering
access point for reserved resources for access communication
involving the wireless network access point; and a third module
that delivers the access probe to the wireless network access
point.
50. A computer program product, comprising: a computer-readable
medium, comprising: a set of codes for causing a computer to obtain
a set of wireless signal access resources employed by a wireless
network access point; an additional set of codes for causing the
computer to negotiate with a neighboring or interfering access
point for reserved resources for access communication involving the
wireless network access point; and a further set of codes for
causing the computer to deliver the access probe to the wireless
network access point.
Description
CLAIM OF PRIORITY UNDER 35 U.S.C .sctn.119
[0001] The present Application for Patent claims priority to U.S.
Provisional Application No. 61/080,045 entitled ACCESS MECHANISMS
FOR LOW POWER BASE STATIONS IN HETEROGENEOUS NETWORKS filed Jul.
11, 2008, assigned to the assignee hereof and expressly
incorporated by reference herein.
BACKGROUND
[0002] I. Field
[0003] The following relates generally to wireless communication,
and more specifically to allocation of wireless resources to access
communications to facilitate improved access for semi-planned or
unplanned wireless networks.
[0004] II. Background
[0005] Wireless communication systems are widely deployed to
provide various types of communication content such as, e.g. voice
content, data content, and so on. Typical wireless communication
systems can be multiple-access systems capable of supporting
communication with multiple users by sharing available system
resources (e.g., bandwidth, transmit power). Examples of such
multiple-access systems can include code division multiple access
(CDMA) systems, time division multiple access (TDMA) systems,
frequency division multiple access (FDMA) systems, orthogonal
frequency division multiple access (OFDMA) systems, and the
like.
[0006] Generally, wireless multiple-access communication systems
can simultaneously support communication for multiple mobile
devices. Each mobile device can communicate with one or more base
stations via transmissions on forward and reverse links. The
forward link (or downlink) refers to the communication link from
base stations to mobile devices, and the reverse link (or uplink)
refers to the communication link from mobile devices to base
stations. Further, communications between mobile devices and base
stations can be established via single-input single-output (SISO)
systems, multiple-input single-output (MISO) systems,
multiple-input multiple-output (MIMO) systems, and so forth.
[0007] Wireless messages are typically sub-divided in time,
frequency, according to codes, and so on, to coordinate
communication between access point and access terminal, and to
reduce interference between multiple concurrent transmissions. For
instance, in an orthogonal frequency division multiple access
(OFDMA) system, forward link messages are segmented into time and
frequency subdivisions. As one example, a signal can be considered
two-dimensional comprising time and frequency, and segmented into
multiple frequency sub-bands, and multiple time sub-frames. Each
time-frequency sub-division is considered a resource of the OFDMA
wireless signal. Furthermore, sets of resources can be configured
to carry particular data. For instance, in each time sub-frame,
frequency sub-bands at the edge of a spectrum bandwidth can be
blanked to reduce cross-talk (guard bands), one set of sub-bands
can be reserved for acquisition and control information, another
set can be reserved for traffic data, and so on. By analyzing
particular frequencies, a device receiving the signal can extract
the acquisition and control information from the signal, ignore
irrelevant user traffic, and the like.
[0008] Further to the above, control and acquisition information is
typically set apart (e.g., in time or frequency) from a
traffic-related portion of a wireless signal. As an example, pilot
signals carrying network acquisition data are often transmitted on
multiple frequency channels, distributed throughout a frequency
spectrum employed for the wireless signal. In some systems, pilot
signals can also be transmitted at higher amplitude than traffic
signals, or even other control signals. This arrangement can yield
improved distinction of application-related information and
acquisition information at a receiver.
[0009] Upon identifying a pilot signal, a receiving device
typically analyzes the signal to identify a source of the signal.
For instance, a transmitting base station typically includes a
distinct identifier or code into its pilot signals. The identifier
can be used to distinguish the base station from other access
points, as well as identify a network associated with the access
point. In some cases, a pilot signal might also specify default
uplink resources for transmitting an acquisition probe to the base
station. In general though, once a pilot signal is obtained, a
receiving device can determine whether and how to proceed in
communicating with the transmitting base station.
[0010] Recent advancements in wireless communications have seen
various types of base stations deployed within a common area,
resulting in a heterogeneous access point network. Although such
networks can be useful to provide different kinds of wireless
communication for different subscribers, additional complexities
can result. For instance, typical interference reduction techniques
that work well for planned, homogeneous base station deployments
may not be as effective in unplanned or heterogeneous access point
networks. Accordingly, current development efforts in wireless
communications involve signal access and acquisition techniques for
restricted access base stations, low and medium power base
stations, unplanned deployments, and various combinations
thereof.
SUMMARY
[0011] The following presents a simplified summary of one or more
aspects in order to provide a basic understanding of such aspects.
This summary is not an extensive overview of all contemplated
aspects, and is intended to neither identify key or critical
elements of all aspects nor delineate the scope of any or all
aspects. Its sole purpose is to present some concepts of one or
more aspects in a simplified form as a prelude to the more detailed
description that is presented later.
[0012] The subject disclosure provides for improved access
communication for wireless systems. According to some aspects of
the subject disclosure, specific wireless resources can be
designated for a set of base stations in a wireless communication
environment. Other base stations can blank or transmit with reduced
power on resources reserved for another set of base stations. In at
least one aspect, the set of base stations can be categorized as a
function of base station type, such as base station transmit power,
base station service area, or base station access type (e.g.,
restricted, general). Accordingly, sets of base stations can expect
mitigated interference at least from different categories of base
stations.
[0013] According to other aspects of the subject disclosure, access
resources can be designated to one or more base stations based on
network load or prevailing interference conditions. Thus, when load
or interference is high, a resource re-use scheme can be employed
that aggressively mitigates interference. Conversely, when load or
interference is light, a less aggressive re-use scheme, or
non-re-use scheme can be employed to lower processing requirements
of wireless devices. In at least one aspect of the subject
disclosure, devices can monitor network load or interference
conditions over time and update interference mitigation schemes
periodically to compensate for dynamic load or interference
conditions.
[0014] According to particular aspects of the subject disclosure,
provided is a method of facilitating access to a wireless
communication environment comprising diverse types of wireless
access points. The method can comprise employing a processor to
parse a set of wireless resources dedicated for access
communication and employ a re-use algorithm to generate a subset of
the wireless resources reserved at least for a particular network
access point. Moreover, the method can comprise outputting the
generated subset to a wireless transmitter for broadcast
transmission to facilitate terminal access to the particular
network access point.
[0015] According to further aspects, provided is an apparatus that
facilitates communication with a network. The apparatus can
comprise memory that includes stored protocols that identify
wireless signal resources for network access communication
involving the apparatus. In addition, the apparatus can comprise a
wireless transmitter for broadcasting a subset of wireless
resources employed for access communication with the apparatus.
Moreover, the apparatus can comprise a data processor that executes
a re-use module that establishes a re-use scheme for access
resource selection based at least on network load or interference
conditions and a selection module that employs the re-use scheme to
generate the subset of wireless resources from a set of network
access resources.
[0016] In other aspects, disclosed is an apparatus for wireless
communication. The apparatus can comprise means for employing a
processor to obtain a set of wireless resources employed for access
communication with a particular network access point. Additionally,
the apparatus can comprise means for employing the processor to
modify the set of wireless resources based on changes in network
load or interference conditions. Furthermore, the apparatus can
comprise means for employing a wireless transmitter to broadcast
the set of wireless resources to facilitate terminal access to the
particular network access point.
[0017] According to one or more other aspects, the subject
disclosure provides at least one processor configured for wireless
communication. The processor(s) can comprise a first module that
parses a set of wireless resources dedicated for access
communication. Additionally, the processor(s) can comprise a second
module that employs a re-use algorithm to generate a subset of the
wireless resources reserved at least for a particular network
access point. Moreover, the processor(s) can comprise a third
module that outputs the generated subset for broadcast transmission
to facilitate terminal access to the particular network access
point.
[0018] In still other aspects, the subject disclosure provides a
computer program product comprising a computer-readable medium. The
computer-readable medium can comprise a set of codes for causing a
computer to parse a set of wireless resources dedicated for access
communication. Further, the computer-readable medium can comprise
an additional set of codes for causing the computer to employ a
re-use algorithm to generate a subset of the wireless resources
reserved at least for a particular network access point. The
computer-readable medium can comprise a further set of codes for
causing the computer to output the generated subset for broadcast
transmission to facilitate terminal access to the particular
network access point.
[0019] Further to the above, the subject disclosure provides a
method of accessing a wireless network. The method can comprise
employing a wireless receiver to obtain a set of wireless signal
access resources employed by a wireless network access point.
Additionally, the method can comprise employing a data processor to
select a subset of the wireless signal access resources for
transmission of an access probe to the wireless network, wherein
the access probe comprises DL resources reserved by a neighboring
or interfering access point. Furthermore, the method can comprise
employing a wireless transmitter to deliver the access probe to the
wireless network access point.
[0020] According to other aspects, disclosed is an apparatus for
wireless communication. The apparatus can comprise a wireless
transceiver for sending and receiving wireless signals and memory
that stores network protocols for identifying access channels
employed by network access points. Furthermore, the apparatus can
comprise a data processor configured to execute a set of modules.
The set of modules includes a preference module that monitors
received DL signals and identifies a preferred network access point
from the signals, an access module that employs the stored
protocols to obtain access communication resources specified for
the preferred network access point and a signaling module that
generates an access probe to be transmitted by the wireless
transceiver over the specified resources.
[0021] In still other aspects, disclosed is an apparatus for
accessing a wireless network. The apparatus can comprise means for
employing a wireless receiver to obtain a set of wireless signal
access resources employed by a wireless network access point.
Furthermore, the apparatus can comprise means for employing a data
processor to negotiate with a neighboring or interfering access
point for reserved resources for access communication involving the
wireless network access point. Further to the above, the apparatus
can comprise means for employing a wireless transmitter to deliver
the access probe and reserved resources to the wireless network
access point.
[0022] In at least one aspect, the subject disclosure provides at
least one processor configured for wireless communication. The
processor(s) can comprise a first module that obtains a set of
wireless signal access resources employed by a wireless network
access point. Further, the processor(s) can comprise a second
module that negotiates with a neighboring or interfering access
point for reserved resources for access communication involving the
wireless network access point and a third module that delivers the
access probe and reserved resources to the wireless network access
point.
[0023] According to still other aspects, the subject disclosure
provides a computer program product comprising a computer-readable
medium. The computer-readable medium can comprise a set of codes
for causing a computer to obtain a set of wireless signal access
resources employed by a wireless network access point. The
computer-readable medium can also comprise an additional set of
codes for causing the computer to negotiate with a neighboring or
interfering access point for reserved resources for access
communication involving the wireless network access point.
Furthermore, the computer-readable medium can comprise another set
of codes for causing the computer to deliver the access probe and
reserved resources to the wireless network access point.
[0024] To the accomplishment of the foregoing and related ends, the
one or more aspects comprise the features hereinafter fully
described and particularly pointed out in the claims. The following
description and the annexed drawings set forth in detail certain
illustrative aspects of the one or more aspects. These aspects are
indicative, however, of but a few of the various ways in which the
principles of various aspects can be employed and the described
aspects are intended to include all such aspects and their
equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 depicts a block diagram of an example apparatus that
facilitates signal acquisition in heterogeneous access point
networks according to disclosed aspects.
[0026] FIG. 2 illustrates a block diagram of example wireless
resources for disparate wireless access technologies according to
further aspects.
[0027] FIG. 3 illustrates a block diagram of example resource
re-use algorithms according to additional aspects of the subject
disclosure.
[0028] FIG. 4 depicts a block diagram of an example system that
allocates access resources based on network performance
measures.
[0029] FIG. 5 illustrates a block diagram of an example network
performance--threshold relationship for selecting access re-use
schemes according to further aspects.
[0030] FIG. 6 depicts a block diagram of an example apparatus for
targeted wireless network acquisition according to particular
aspects disclosed herein.
[0031] FIG. 7 illustrates a block diagram of an example system for
interference mitigation in a heterogeneous access point wireless
environment.
[0032] FIG. 8 depicts a flowchart of a sample methodology for
facilitating signal acquisition for low power network access points
according to some aspects.
[0033] FIG. 9 illustrates a flowchart of an example methodology for
dynamic resource allocation based on network performances
measures.
[0034] FIG. 10 depicts a flowchart of a sample methodology for
wireless network acquisition according to one or more disclosed
aspects.
[0035] FIG. 11 illustrates a flowchart of a sample methodology for
facilitating over-the-air interference mitigation according to
further aspects.
[0036] FIGS. 12 and 13 illustrate block diagrams of example systems
for providing and facilitating, respectively, improved access
resource allocation.
[0037] FIG. 14 depicts a block diagram of an example wireless
transmit-receive chain facilitating wireless communication
according to one or more aspects.
[0038] FIG. 15 depicts a block diagram of a sample cellular
communication environment according to general aspects of the
subject disclosure.
[0039] FIG. 16 illustrates a block diagram of an example system
that enables semi or unplanned deployment of low power or
restricted access base stations.
DETAILED DESCRIPTION
[0040] Various aspects are now described with reference to the
drawings, wherein like reference numerals are used to refer to like
elements throughout. In the following description, for purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of one or more aspects. It can be
evident, however, that such aspect(s) can be practiced without
these specific details. In other instances, well-known structures
and devices are shown in block diagram form in order to facilitate
describing one or more aspects.
[0041] In addition, it should be apparent that the teaching herein
can be embodied in a wide variety of forms and that any specific
structure and/or function disclosed herein is merely
representative. Based on the teachings herein one skilled in the
art should appreciate that an aspect disclosed herein can be
implemented independently of any other aspects and that two or more
of these aspects can be combined in various ways. For example, an
apparatus can be implemented and/or a method practiced using any
number of the aspects set forth herein. In addition, an apparatus
can be implemented and/or a method practiced using other structure
and/or functionality in addition to or other than one or more of
the aspects set forth herein. As an example, many of the methods,
devices, systems and apparatuses described herein are described in
the context of providing cell-specific signal coding for reference
signals in a wireless communication environment. One skilled in the
art should appreciate that similar techniques could apply to other
communication environments.
[0042] Planned deployments of wireless base stations (BSs) in a
wireless access network (AN) typically consider position, spacing
and transmission/receive characteristics of transceiver devices.
One goal of planned base station deployment is to reduce
interference among transmitters. Thus, for instance, one deployment
plan might space different base stations apart by a distance
approximately equal to their respective maximum transmit ranges. In
this type of deployment, signal interference between the base
stations is minimized.
[0043] In unplanned or semi-planned BS deployments, wireless
transmitters are often not positioned to reduce interference.
Instead, it is not unusual with semi or unplanned deployments for
two or more transmitting BSs (e.g., that transmit into
substantially 360 degrees) to be in close proximity. Furthermore,
such deployments often include base stations that transmit at
significantly different power, covering a wide range of service
areas (e.g. also referred to as a heterogeneous transmit power
environment). As an example, a high power BS (e.g. macro cell at 20
watts) may be situated proximate a mid or low power transmitter
(e.g., micro cell, pico cell, femto cell, etc., of varying
transmission power, e.g., 8 watts, 3 watts, 1 watt, and so on). The
higher power transmitter can be a significant source of
interference for the mid and/or low power transmitters.
Furthermore, lower power transmitters can be a significant source
of interference for the high power BS, particularly for terminals
close to such transmitters. Accordingly, signal interference in
semi or un-planned environments and/or heterogeneous transmit power
environments can often be a significant problem as compared with
the conventional planned macro base station AN.
[0044] In addition to the foregoing, restricted access (RA) BSs can
compound problems resulting from semi and un-planned BS deployment.
For instance, an RA BS can selectively provide access to one or
more terminal devices, denying network access to other such
devices. Accordingly, devices are forced to search for other BSs if
denied access, and often observe significant interference from the
denying BS. As utilized herein, an RA BS can also be termed a
private BS (e.g. a Femto cell BS or a home Node B [HNB]), or some
similar terminology.
[0045] Although RA BSs add network complexity, they do provide
significant utility. For instance, a personal RA BS can be
installed privately in a home, at an office, etc., utilizing
private networking resources for voice and or data access (e.g. to
the Internet and/or to a mobile operator's network). Such an
arrangement can provide great individual control over a
subscriber's network access via the personal RA BS. However,
because the network interface utilizes a subscriber's private
network resources, rather than resources maintained by a network
operator, the owner of such a BS might not want those resources
utilized by general access mobile users; accordingly, an RA BS is
typically configured to limit access to pre-specified terminal
devices, preserving resources for authorized users.
[0046] Further to the above, un-planned, heterogeneous and RA
deployments can lead to poor geometric conditions for a wireless
AN. Even without restricted association, a device that observes a
very strong signal from a macro BS could be configured to prefer to
connect to a pico BS, because the pico BS is "closer" to the
terminal in terms of path-loss. Thus, the pico BS is capable of
serving the terminal at a comparable data rate while causing less
interference to the wireless AN. However, a terminal monitoring the
pico BSs signal (e.g., a preamble comprising control and
acquisition information) will observe significant interference from
the macro BS, resulting in a low signal to noise ratio (SNR) at the
terminal (e.g., possibly rendering the pico BS undetectable by the
BS).
[0047] Additional problems can also result when an RA BS is
introduced into the heterogeneous BS environment, discussed above.
In such a case, a terminal device can be very close to a BS to
which it is not allowed to connect, observing signals of such BS at
very high level. Accordingly, this BS will cause strong
interference (and, e.g. resulting in very low SNR) for a BS serving
the terminal (e.g., the closest BS the terminal is allowed to
connect to), and likewise can cause high interference to terminals
served by the RA BS. In some cases, the interference can be so
strong as to desensitize an analog/digital (A/D) converter of the
terminal. To illustrate the problem of desensitization, components
of a terminal can typically be configured based on total received
signal strength plus an interference level (which, e.g., can be
dominated by the RA BS in the above scenario). Where the signal
level of the serving BS is extremely low relative the nearby RA BS,
such signal can be below a quantization noise level. In this case,
even if the interfering BS is present on different frequency
resources of a wireless signal than the serving BS (e.g., a
different sub-carrier or set of sub-carriers), the interfering BS
can still render the serving BS undetectable at the terminal, the
latter being masked by quantization noise.
[0048] As described herein, several aspects of the subject
disclosure are provided to address the foregoing problems or
similar network communication and/or access problems. In one
example, orthogonal wireless resources employed for access
communications (e.g., an uplink acquisition probe, a downlink
acquisition grant or denial, related acquisition communication) can
be allocated to particular base stations or different types of base
stations based on a re-use scheme. As utilized herein, re-use
refers to segmentation of a set of wireless resources into distinct
subsets thereof, and allocating different subsets different
categories of transmitters (e.g., BSs, or access terminals) or
wireless traffic (e.g., access and acquisition traffic, control
traffic, voice traffic, data traffic, and so on). Thus,
transmitters within a particular category, or transmitting a
particular category of traffic, transmit on an assigned set of
resources, and either blank or transmit with reduced power on
resources assigned to other categories of transmitters or
traffic.
[0049] As an example, consider an orthogonal frequency division
multiple access (OFDMA) system with 100 kilohertz (kHz) frequency
band reserved for access communications. To implement re-use for
access communications, the 100 kHz band can be further segmented,
e.g. into ten orthogonal sub-bands of 10 kHz each, and different
categories of devices or traffic assigned to respective sub-bands.
As a more specific example for DL transmission, different sub-bands
or sets of sub-bands can be allocated to different types of BSs,
including access type (e.g., restricted access, general access),
transmit power type (e.g. 50 watt, 25 watt, high power, mid power,
etc.), or cell type (e.g., macro cell, micro cell, pico cell, femto
cell), or the like, or combinations thereof. Thus, in a
heterogeneous access point environment comprising macro cells and
femto cells, a re-use scheme might assign nine access sub-bands to
either type of base station, and reserve a tenth access sub-band
just for femto cells. Accordingly, if a femto cell observes high
interference from the macro cells, the tenth sub-band can be
employed; otherwise the femto cell can employ any of the ten
sub-bands. It should be appreciated, however, that the subject
disclosure is not limited to the particular allocation of resources
cited in the above example (or other specific examples described
herein). Rather, other associations between different categories of
transmitters, traffic, etc., and different subsets of access
resources, known in the art or made known to one of skill in the
art by way of the context provided herein, are within the scope of
the subject disclosure.
[0050] Various forms of resource re-use are presented herein.
Examples of different forms of re-use, or re-use schemes, include
natural re-use, random re-use (or pseudo-random re-use) and planned
re-use. Natural re-use involves a determination of current load and
an estimate of interference at a receiver, for a common access
channel. Access terminals can select a resource (e.g.,
time-frequency segment) on the common channel to transmit an access
probe. With a relatively small terminal load on the access channel,
minimal overlap of selected access resources occurs, creating a
natural re-use on the common band.
[0051] Further to the above, different types of waveforms, such as
OFDMA, single carrier frequency division multiple access (SC-FDMA),
time-division or frequency-division code division multiple access
(CDMA), etc., can be utilized on the common access channel. For
instance, a common CDMA segment can be assigned for CDMA access
terminals to transmit their access probes. In this case, CDMA
processing gain (spreading factor) and the CDMA segment
allocation/dimensioning can be implemented in a manner that results
in relatively small load on the CDMA segment. In such
circumstances, a lower power base station can detect a weak access
probe even in the presence of relatively strong interference (e.g.,
from a macro cell).
[0052] According to other aspects of the subject disclosure,
interference avoidance for access communication can be implemented
with a random re-use scheme, or planned re-use scheme. With random
re-use, an access channel is sub-divided into subsets of access
resources, and transmitters employ a random or pseudo-random
algorithm to select a resource for the access communication (e.g.,
transmitting or responding to an access probe). Where network load
is moderate compared with the number of available access resources,
random re-use can mitigate interference for access communication.
For planned re-use, access resources are reserved for particular
BSs or types of BSs. Reservation of resources can be based on
negotiations between BSs, comparing respective quality of service
(QoS) requirements, current load, and so on, of the different BSs,
or can be determined at a central planning component (e.g., a radio
network controller [RNC]) based on similar criteria. Reservation of
resources in a planned re-use scheme can be implemented for a
limited time, indefinitely, for a default time, until load or
interference conditions change, or the like.
[0053] In one particular aspect of the subject disclosure, re-use
schemes are implemented dynamically based on changing interference
or network load conditions. Measurements of network load are
obtained and compared with different load thresholds. Degrees of
load thresholds can be based, for instance, on acceptable
interference levels on particular access resources. Where
load/interference measurements are below a minimum threshold,
natural re-use can be employed, where different transmitters
independently select resources of a common access channel. Where
load/interference measurements rise above the minimum threshold,
random re-use can be employed, to increase likelihood of
distributed use of subsets of channel resources. On the other hand,
where load/interference measurements rise above a maximum
threshold, planned re-use can be implemented to spread existing
terminals among the subsets of access resources. Further to the
above, when load or interference drops below the maximum threshold,
random re-use can be implemented, saving processing resources
involved with resource negotiations. Additionally, if load or
interference drops below the minimum threshold, natural re-use can
again be implemented to further reduce processing associated with
resource selection.
[0054] Referring now to the figures, FIG. 1 illustrates a block
diagram of an example system 100 according to aspects of the
subject disclosure. System 100 comprises a signal acquisition
apparatus 102 having an interface with a wireless transceiver 116.
Signal acquisition apparatus 102 is configured to obtain wireless
signal resources and select a subset of the resources according to
a re-use scheme. The subset can be employed by wireless transceiver
116 for transmitting or receiving wireless communication signals
related to network access, access grant, or related tasks. In some
aspects of the subject disclosure, signal acquisition apparatus 102
can be installed at a wireless BS (e.g., macro cell, micro cell,
femto cell, etc.). In other aspects, signal acquisition apparatus
102 can be implemented as part of a network control component
(e.g., an RNC) communicatively coupled with one or more wireless
BSs (116) for centralized resource allocation.
[0055] Signal acquisition apparatus 102 comprises a data processor
104 for executing one or more resource selection modules (106, 108)
stored in memory 114. Particularly, data processor 104 can execute
a re-use module 106 that establishes a re-use scheme for wireless
communications of wireless transceiver 116. A particular re-use
scheme established by re-use module 106 can be based on one or more
criteria associated with the wireless transceiver 116, or traffic
supported by wireless transceiver 116. In one aspect of the subject
disclosure, the re-use scheme can be based at least in part on a
type of wireless network BS that is associated with wireless
transceiver 116. Thus, for instance, a first re-use scheme can be
established if transceiver 116 is associated with a macro BS and a
different re-use scheme if transceiver 116 is associated with a
femto BS. As an alternative, the re-use scheme could be based on
whether the wireless network BS is a general access BS or a
restricted access BS (e.g., having a limited set of associated
access terminals). In other aspects of the subject disclosure, the
re-use scheme can be selected based on current or anticipated load
at the wireless transceiver 116. In yet other aspects, the re-use
scheme can be selected based on UL or DL interference measurements
determined by the wireless transceiver 116 or a terminal served by
the wireless transceiver 116, respectively. In still other aspects,
the re-use scheme can be established based on a combination of the
foregoing criteria, or similar criteria.
[0056] The re-use scheme is output as a file 108 to a selection
module 110. Selection module 110 employs the re-use scheme 108 to
identify a subset of access communication resources to be employed
by wireless transceiver 116 for access-related communication. For a
natural re-use scheme, selection module 110 can allocate the full
bandwidth of an access channel. Alternatively, a subset of the full
bandwidth can be allocated based on a fixed identifier associated
with wireless transceiver 116 (e.g. a distinct BS identifier) or an
identifier of a terminal served by wireless transceiver 116. For a
random re-use scheme, selection module 110 can execute a random or
pseudo-random algorithm stored in memory 114 to select a subset of
resources (e.g., time-frequency resources, code resources, symbol
resources, and so on) of the access channel. For a planned re-use
scheme, selection module 110 can employ negotiation instructions
stored in memory 114 to obtain criteria affecting communication
quality from wireless transceiver 116 and at least one other
wireless BS (not depicted). Based on comparison of the respective
quality criteria (e.g., including current load, QoS commitments,
measured interference, or the like), a subset of access channel
resources can be established for use by wireless transceiver
116.
[0057] Selected resources are output in a resource file 112, and
stored in memory 114. Where signal acquisition apparatus 102 is a
network component separate from a BS, the resource file 112 can be
conveyed to the BS (116) for communication scheduling. Where signal
acquisition apparatus 102 is a part of the BS, data processor 104
can be employed to schedule access communication based on the
selected resources 112. Wireless transceiver 116 can then broadcast
the selected resources 112 to mobile devices served by the BS. Upon
receiving the broadcast, such devices can identify UL resources for
transmitting an access grant to wireless transceiver 116, and tune
to particular DL resources over which the wireless transceiver 116
will respond.
[0058] By employing various re-use schemes for allocation or
selection of orthogonal wireless resources, various levels of
network load can be accommodated while mitigating network
interference. This flexibility can also result in increased
scalability for the network. In some aspects, signal acquisition
for lower power BSs within a macro coverage area can be improved,
by allocating particular resources for such BSs. Particularly,
where the macro cell is configured to blank or transmit at reduced
power on resources allocated to lower power BSs, reduced
interference for various types of BSs transmitted at various power
levels can often result.
[0059] FIG. 2 depicts example illustrations 200 of segmented
wireless signal resources 202, 204 for different wireless access
technologies. An example OFDM signal is depicted at 202. The
horizontal axis represents time, while the vertical axis represents
frequency. As depicted, signal 202 is divided into multiple time
resources 202A, or time sub-slots, along the horizontal axis and
multiple frequency resources 202B, or frequency sub-bands, along
the vertical axis. Each intersection of a frequency sub-band and a
time sub-slot is a single time-frequency resource 202C. Wireless
data transmitted during a particular time sub-slot and at a
particular frequency sub-band is therefore transmitted on a
corresponding time-frequency resource (202C).
[0060] For multiple access systems, there may be many access
terminals connected to or attempting to connect to a network
concurrently. If more than one of these terminals sends data on a
single time-frequency resource (202C), significant interference can
result at a receiver. If the receiver can still distinguish
interfering signals, the communication may be able to persist. In
such a case, a natural re-use scheme where a full access channel
bandwidth (202B) or significant portion thereof is employed for
access communication may be sufficient. Where interference among
transmitters does degrade wireless communications beyond an
acceptable level, random re-use can be employed by the terminals
(or by a BS) to randomly select particular tones/resources 202C for
respective transmitters, reducing likelihood that the interfering
transmitters employ common resources. Where interference among the
transmitters is especially severe, a planned re-use can be employed
to ensure that the transmitters are employing distinct orthogonal
resources. In some instances, where interference is severe or where
a desired signal is especially low, planned re-use can allocate
different time sub-slots to different transmitters, and require the
transmitters to blank a sub-slot allocated to the other
transmitter.
[0061] Wireless signal 204 is a CDMA signal comprising multiple
spreading factors (SF). CDMA signals employ different code
sequences to spread data transmitted at a particular frequency,
over a wide range of frequency bands. This spreading is determined
by a particular code employed, and reduces interference between
concurrent transmissions at different spreading factors. As
depicted, the CDMA signal 204 comprises an SF1 segment 204A, an SF2
segment 204B, an SF 4 segment 204C, and SF8 segment 204D, and SF16
segment 204E and an SF 32 segment 204F. It should be appreciated,
however, that the signal 204 can be further segmented into higher
order spreading factors. Assigning different resources for
different transmitters enables concurrent wireless communications
for several devices. Additionally, by employing re-use schemes
described herein, flexibility and scalability can be afforded even
for heterogeneous access point environments.
[0062] FIG. 3 illustrates example UL resource allocation for an
OFDMA system based on different re-use schemes described herein. It
should be appreciated that the resource allocation and signal
resource segmentation are for illustrative purposes, and are not
exclusive. Rather, other suitable access channel configurations, or
re-use configurations can be implemented within the scope of the
subject disclosure.
[0063] An example natural re-use scheme is depicted at 302.
Wireless signal 302 comprises an example set of access channel
resources, depicted as grayed out resource blocks 302A. The access
channel resources 302A comprise the full spectrum bandwidth, during
four different time sub-slots. Where network load is relatively
light, resulting in few concurrent transmissions on the access
channels 302A in any given time frame of wireless signal 302, a
natural re-use on these channels 302A results. In such case,
transmitters can employ the entire channel spectrum 302A for access
communications (e.g., during DL frames for BSs, and UL frames for
access terminals) with minimal interference. Alternatively, the
transmitters can select a subset of the channels 302A using various
criteria (specified by a terminal manufacturer, by a wireless
network, or the like). In one case, selection of the subset of
resources can be based on an identifier associated with the
respective transmitter. Since transmitter identifiers (e.g. media
access [MAC] address, serial number, or the like) are typically
distinct, a selection algorithm employing a distinct or unique
identifier can often in distinct subsets of access resources 302A,
further reducing likelihood of concurrent transmissions on
identical resources.
[0064] Wireless signal 304 depicts a random allocation of subsets
of resources from access channels 302A. Particularly, signal 304
depicts UL resources selected by different access points, access
point 1 (lined fill) and access point 2 (dotted fill). For random
allocation, each respective access point independently employs a
random or pseudo-random function to select a number of
time-frequency resources for access communications. The number of
resources can further depend on QoS commitments, current wireless
conditions, current load, or the like. For instance, if an access
point is near load capacity, a larger number of resources can be
selected with the algorithm(s). Although random re-use can result
in overlapped resources 304A (in which multiple access points
select the same time-frequency resource for access-related
communication), such occurrences will be statistically infrequent
if a network access point is below a particular load threshold
(compared with a number of available resources, and number of
resources selected per transmitter). Additionally, random re-use
can be implemented independently by different transmitters,
resulting in minimal processing overhead and minimal resource
selection times.
[0065] Wireless signal 306 depicts a planned re-use allocation of
respective subsets of access channel 302A resources. The planned
re-use is implemented via negotiations between different
transmitters, or by a central controller that can obtain pertinent
information from the different transmitters. In one aspect of the
subject disclosure, different BSs can exchange data pertaining to
current or anticipated access channel traffic requirements (e.g.,
via a backhaul network). The BSs can employ an allocation algorithm
that assigns a subset of resources to specified BSs based on
respective requirements. BSs with higher requirements can be
assigned a greater number of resources, or higher priority
resources, or the like. Additionally, a BS will typically blank, or
transmit with reduced power on, a resource assigned to a different
BS. The BS can transmit up to full power on resources assigned to
it, on the other hand. Accordingly, planned resource re-use
minimizes resource overlap by specifically reserving resources for
particular BSs. A similar mechanism can also be applied for UL
resources allocated to access terminals.
[0066] In at least one other aspect of the subject disclosure, an
access terminal can negotiate to secure UL resources for itself, or
DL resources for a BS serving the access terminal. In the former
case, the access terminal requests allocated resources from the
serving BS, which instructs other access terminals to transmit with
reduced power on the allocated resources. Alternatively, or in
addition, the access terminal can request neighboring cells for
allocation of UL resources as well. The serving or neighboring
BS(s) can grant the request based on various criteria, including
current load, resource availability, anticipated load/availability,
QoS requirements for the access terminal versus other terminals, a
quality stipulation in a subscription plan associated with the
access terminal, or like criteria, or combinations thereof
[0067] For DL resources, the access terminal can send an
interference avoidance request to a BS neighboring or interfering
with the serving BS. The avoidance request can specify a set of
resources selected by the serving BS or by the access terminal
(e.g., based on a random or planned re-use scheme). The access
terminal can negotiate with the neighboring/interfering BS (e.g.
utilizing negotiation rules specifying resource allocation as a
function of QoS commitments, current/anticipated load, etc.) and
convey an agreement provided by such BS to the serving BS.
[0068] In at least one aspect of the subject disclosure, an access
terminal served by a low power BS, or a restricted access BS, can
attempt to secure interference avoidance from a nearby macro cell.
Based on network resource reservation rules, the macro cell can
approve or deny the avoidance request, and transmit a response to
the access terminal. If the request is approved, the macro cell can
specify the reserved resources as well as a default time over which
the agreement will be observed. After such time, the macro can
resume transmitting or transmitting at full power on the reserved
resources, unless a subsequent agreement is reached based on the
network rules or supplemental rules (e.g., defining macro behavior
in successive interference avoidance requests). In such a manner,
femto BSs can operate within a larger macro environment with
mitigated interference.
[0069] FIG. 4 illustrates a block diagram of an example system 400
according to particular aspects of the subject disclosure. System
400 comprises a base station transmitter 402 coupled with a signal
acquisition apparatus 404. Signal acquisition apparatus 404 is
configured to dynamically implement resource re-use for access
communications pertaining to base station transmitter 402.
According to some aspects of the subject disclosure, the resource
re-use depends on a category of the base station transmitter 402,
of wireless traffic maintained by transmitter 402, or of access
terminals served by the transmitter 402. Alternatively, or in
addition, the resource re-use can be dependent on prevailing
network load and interference conditions. As conditions change,
different re-use schemes can be implemented to balance signal
interference with processing requirements and delay associated with
the various re-use schemes.
[0070] Signal acquisition apparatus 404 can comprise an interface
module 408 communicatively coupled with a radio network controller
(RNC) 406 via a terrestrial radio access network (TRAN)/control
network interface. The RNC 406 can further comprise an upper layer
signaling module 410 that obtains estimates of network load for
base station transmitter 402. Additionally, the upper layer
signaling module 410 can obtain estimates of network load from
neighboring transmitters (not depicted), including neighboring
macro cells, as well as neighboring micro, pico or Femto cells. For
macro cells, network load can be obtained from service estimates
and separate traffic flows served by base station transmitter 402,
as well as the neighboring macro cells. The load information can be
maintained in a network database (not depicted), and accessed by
the upper layer signaling module 410. A similar mechanism can be
employed for other access points coupled with RNC 406 (e.g., micro
or pico cells). For Femto cells, network load estimates can be
obtained directly from the Femto cells (e.g., via an Internet
connection between the Femto cell and wireless network), or from
access terminals served by the Femto cells, which bundle the load
estimate into an upper layer signaling message and transmit the
message to base station transmitter 402 (which can forward the
message to RNC 406 via interface module 408). According to some
aspects of the subject disclosure, base stations (or access
terminals) can also upload QoS commitments for respective traffic
supported by the base stations to the network. The QoS commitments
can be stored in the above network database and accessed by upper
layer signaling module 410. The upper layer signaling module 410
can filter load estimates (and QoS commitments) pertinent to base
station transmitter 402, and provide such information to signal
acquisition apparatus 404 in a BS load message 412.
[0071] A selection module 414 can access the load message 412 to
determine relative loading for base station transmitter 402.
Additionally, selection module 414 can access a set of interference
thresholds 418 stored in memory at signal acquisition apparatus
404. Based on current or anticipated load and measured or estimated
interference relative the interference thresholds (e.g., see FIG.
5, infra), selection module 414 can select a re-use scheme for base
station transmitter 402, as described herein.
[0072] In at least one aspect of the subject disclosure, selection
of access resources can be based instead (or in addition) on a
category of the transmitter 402 established by a classification
module 420. Specifically, classification module 420 can establish a
set of base station categories based on different transmit power,
access association, cell type, or the like, or a combination
thereof. As one example, classification module 420 can classify
high power base stations (e.g., over 20 watt) and low power base
stations (e.g., under 20 watt), as well as general access and
restricted access base stations. Based on the particular
classification, a predetermined set of access resources can be
assigned to base station transmitter 402 and
neighboring/interfering base stations. Allocating resources based
on base station category can be implemented independently of re-use
scheme, or in conjunction with a planned re-use scheme, for
instance. Accordingly, where interference at base station
transmitter 402 (or an access terminal served by such transmitter
402) exceeds a level associated with planned re-use (e.g.,
established by threshold protocols 418), selection module 414
establishes a subset of access resources allocated for base station
transmitter 402. The allocation can be for a limited period of
time, until load drops below the interference level associated with
planned re-use, or the like.
[0073] It should be further appreciated that interface module 408
can poll RNC 406 for updated network load measurements or QoS
commitments, and provide the updated data to selection module 414.
Based on the updated data, selection module 414 can implement a
different re-use scheme, as established by threshold protocols 418.
Accordingly, system 400 can provide a flexible and adaptive
allocation of resources to mitigate wireless interference for base
station transmitter 402.
[0074] FIG. 5 illustrates a block diagram of an example graph 500
depicting interference at a wireless receiver as a function of
interference thresholds. Graph 500 depicts frequency on a
horizontal axis, and amplitude on a vertical axis. The amplitude
vs. frequency levels can comprise measured interference at
respective frequency bandwidths associated with a wireless network
signal. The measurements comprising graph 500 can be conducted
periodically, triggered based on a predetermined event (e.g.,
transmission of an access probe, receipt of an access probe), or
the like.
[0075] Also as depicted, graph 500 includes a first, second . . .
up to an N.sup.th interference threshold (where N is a positive
integer) specified at varying interference amplitudes. Furthermore,
the respective thresholds can be mapped to particular re-use
schemes. Thus, at 502 interference amplitude at frequency level `3`
and `4` exceed the first threshold. If a receiver measuring the
interference amplitudes displayed at graph 500 employs frequencies
`3`, `4` or `6`, a re-use scheme mapped to the first threshold can
be implemented. At 504, interference at frequency `5` exceeds
threshold `N`; accordingly a receiver employing frequency `5` can
implement a re-use scheme mapped to the N.sup.th threshold.
Likewise, frequencies `1`, `2`, `7` and `8` are below the first
threshold, and thus a default re-use scheme can be employed, such
as natural re-use or no re-use.
[0076] FIG. 6 depicts a block diagram of an example mobile
acquisition apparatus 600 according to aspects of the subject
disclosure. Mobile acquisition apparatus 600 can be employed by a
wireless access terminal (not depicted, but see FIG. 7, infra)
selecting wireless resources for use in transmitting an access
probe to a network access point. Particularly, mobile acquisition
apparatus 600 can identify a preferred network access point for the
mobile terminal, and implement a resource re-use scheme in
communication with the preferred access point.
[0077] Mobile acquisition apparatus 600 can comprise a data
processor 602 that executes a set of modules stored in memory 604.
The modules can comprise a preference module 606 that monitors
received DL signals from network access points, and identifies a
preferred access point from the signals. Specifically, preference
module 606 can analyze pilot signals or other acquisition pilots
transmitted by wireless network access points and obtain an ID from
the respective pilot signals. The IDs can be cross-reference with a
list of preferred access points stored in memory 604. If an ID of a
preferred access point is identified, preference module 606 stores
the ID in memory for use by access module 612. Otherwise, no
preferred ID is stored. In at least one aspect of the subject
disclosure, the preferred access point comprises a femto BS
associated with a host mobile device.
[0078] Data processor 602 can also execute an access module 612
that identifies access communication resources employed by a
wireless network. A measurement module 608 can be employed to
calculate prevailing interference on the identified access
resources. A result 610 of the interference calculations is
provided to access module 612. Additionally, the access module can
employ stored protocols 614 to identify a subset of resources
applicable for access communication. In some aspects, the stored
protocols 614 can include rules for generating the subset of
resources based on various conditions. For instance, the protocols
can result in a first subset of resources if a wireless network
access point is the preferred access point identified by preference
module 606. In other aspects, the rules can result in a various
subsets of resources depending on current load at the wireless
network access point, or based on the interference level calculated
by measurement module 608. Specifically, the rules can comprise
different resource re-use schemes based on various interference
levels, as described herein.
[0079] Once the proper subset of access resources is identified, a
signaling module 614 generates an access probe requesting access to
the wireless network access point. Furthermore, the access probe
can be transmitted on the wireless resources identified by access
module 612. As a result, mobile acquisition apparatus 600 can adapt
to dynamic resource allocation schemes based on a set of rules
stored in memory 604, or obtained from a proximate network (e.g.,
where the network broadcasts the rules).
[0080] FIG. 7 illustrates a wireless network environment 700
comprising heterogeneous types of network access points according
to particular aspects of the subject disclosure. As depicted,
wireless environment 700 comprises a macro BS 402 providing
wireless communication services to a macro cell. Furthermore, the
environment 700 comprises a micro access point (AP) 404 providing
wireless communication services to a micro cell (which can be
partially or wholly within the macro cell). The environment 700
also comprises a Femto AP 706, serving a Femto cell partially or
wholly within the macro cell. Femto AP 706 is a restricted access
base station that maintains a list of access terminals authorized
for network services; other access terminals that are not on the
list are denied network services by the Femto AP 706.
[0081] Additionally, the environment 700 comprises an access
terminal 708 included in the restricted access list maintained by
Femto AP 706. Access terminal 708 can sample transmissions of the
respective base stations 702, 704, 706 and attempt to identify the
access points based on transmitter IDs broadcast in respective
pilot or acquisition signals. Based on the transmitter IDs, access
terminal 708 can identify Femto AP 706 as a preferred access point,
and prepare an access probe to connect to the Femto AP 706.
According to some aspects of the subject disclosure, access
terminal 708 can analyze a broadcast channel employed by Femto AP
706 to obtain acquisition signal resources for transmitting the
access probe. In other aspects of the subject disclosure, access
terminal 708 can identify or generate appropriate acquisition
signal resources (e.g., see FIG. 6, supra) based on the type of the
access point (e.g., restricted access, Femto, low power).
Alternatively, or in addition, the acquisition signal resources can
be based at least in part on relative interference measurements of
the respective APs 702, 704, 706 and a set of interference
thresholds, as described herein. Once the appropriate access
resources are identified, access terminal 708 can transmit the
access probe discussed above, requesting access to Femto AP
706.
[0082] According to particular aspects of the subject disclosure,
access terminal 708 can comprise a mediation module 712 that
facilitates reduced DL interference for a selected or serving
access point. As an example, upon selecting an access point (706)
in the wireless environment 700, access terminal 708 can employ
measurement module 710 to measure DL interference from neighboring
access points (702, 704). If the interference from a particular
access point (702, 704) is above a predetermined threshold,
mediation module 712 can send an interference avoidance request to
the interfering access point (702, 704).
[0083] Optionally, access terminal 708 can specify a subset of DL
resources employed by the selected access point (706) for access
grant/denial messages. The subset of DL resources can be broadcast
by the selected access point (706), or generated by access terminal
708. In one example, access terminal 708 can generate the subset of
resources from network load conditions or prevailing DL
interference conditions transmitted by a network access point (702,
704, 706). Alternatively, or in addition, the subset of resources
can be estimated from interference measurements performed by
measurement module 710.
[0084] If an interference avoidance request is granted by the
neighboring/interfering base station(s) (702, 704), access terminal
708 can include the grant in an access probe or other message
transmitted to the selected access point (706). Optionally, the
message/probe can specify particular resources reserved for the
selected access point (706) as a result of the interference
avoidance request. Access terminal 708 can then monitor the
specified resources for an access grant or access denial in
response to the access probe. By employing selected UL resources
based on measured interference, access terminal 708 can increase
likelihood that the selected access point will receive the probe.
Additionally, by requesting neighboring/interfering access points
to reserve (e.g., transmit with no power or reduced power) selected
DL resources, access terminal 708 can increase likelihood that the
response to the access probe is received as well. Accordingly,
system 700 can result in improved access communication in a
wireless environment.
[0085] The aforementioned systems have been described with respect
to interaction between several components, modules and/or
communication interfaces. It should be appreciated that such
systems and components/modules/interfaces can include those
components/modules or sub-modules specified therein, some of the
specified components/modules or sub-modules, and/or additional
modules. For example, a system could include access terminal 708,
Femto AP 706, base station transmitter 402 and signal acquisition
apparatus 404, or a different combination of these or other
modules. Sub-modules could also be implemented as modules
communicatively coupled to other modules rather than included
within parent modules. Additionally, it should be noted that one or
more modules could be combined into a single module providing
aggregate functionality. For instance, measurement module 710 can
include mediation module 712, or vice versa, to facilitate
calculating signal interference and requesting interference
avoidance by way of a single component. The components can also
interact with one or more other components not specifically
described herein but known by those of skill in the art.
[0086] Furthermore, as will be appreciated, various portions of the
disclosed systems above and methods below may include or consist of
artificial intelligence or knowledge or rule based components,
sub-components, processes, means, methodologies, or mechanisms
(e.g., support vector machines, neural networks, expert systems,
Bayesian belief networks, fuzzy logic, data fusion engines,
classifiers . . . ). Such components, inter alia, and in addition
to that already described herein, can automate certain mechanisms
or processes performed thereby to make portions of the systems and
methods more adaptive as well as efficient and intelligent.
[0087] In view of the exemplary systems described supra,
methodologies that may be implemented in accordance with the
disclosed subject matter will be better appreciated with reference
to the flow charts of FIGS. 8-11. While for purposes of simplicity
of explanation, the methodologies are shown and described as a
series of blocks, it is to be understood and appreciated that the
claimed subject matter is not limited by the order of the blocks,
as some blocks may occur in different orders and/or concurrently
with other blocks from what is depicted and described herein.
Moreover, not all illustrated blocks may be required to implement
the methodologies described hereinafter. Additionally, it should be
further appreciated that the methodologies disclosed hereinafter
and throughout this specification are capable of being stored on an
article of manufacture to facilitate transporting and transferring
such methodologies to computers. The term article of manufacture,
as used, is intended to encompass a computer program accessible
from any computer-readable device, device in conjunction with a
carrier, or storage medium.
[0088] FIG. 8 illustrates a flowchart of an example methodology 800
according to aspects of the subject disclosure. At 802, method 800
can employ a data processor to parse a set of wireless resources
dedicated for access communication. The resources can include one
or more channels specified as default or general use channels for
access communications. At 804, method 800 can employ the data
processor to execute a re-use algorithm that generates a subset of
the wireless resources for a particular network access point. The
re-use algorithm can be employed conditionally, for instance where
network load or network interference rise above a minimum
threshold. At 806, method 800 can broadcast the subset of resources
to access terminals. Terminals can submit access probes utilizing
the specified subset of resources, and reduce interference with
respect to access probes transmitted to neighboring base
stations.
[0089] FIG. 9 depicts a flowchart of a sample methodology 900 for
providing updated re-use based on dynamic network conditions. At
902, method 900 can identify wireless network resources reserved
for access communication. Such communication can comprise UL
resources for transmitting access probes, and DL resources for
responding to such probes. At 904, a determination is made as to
whether a network employs auto-provisioning for re-use selection.
If so, method 900 proceeds to 906; otherwise method 900 proceeds to
926.
[0090] At 906, method 900 can obtain network load measurements. The
load measurements can be UL measurements calculated at a network
receiver, or DL measurements calculated by an access terminal, or
both. AT 908, method 900 can obtain load thresholds (stored in
memory) mapped to one or more re-use schemes, and compare the
network load measurements to the respective thresholds. At 910,
method 900 can make a determination as to whether network
interference is low, medium or high, based on the threshold
comparison. For low interference, method 900 proceeds to 912. For
medium interference, method 900 proceeds to 914. For high
interference, method 900 proceeds to 920.
[0091] At 912, method 900 can select a natural re-use algorithm for
access resources associated with an access point. Natural re-use
can involve transmitting on default access channels. Alternatively,
natural re-use can involve utilizing a set of access channel
resources associated with a particular type of access point (e.g.,
based on transmit power, coverage, association type). From 912,
method 900 proceeds to 932 and broadcasts the selected access
resources determined from the natural re-use algorithm.
[0092] At 914, method 900 can select a random or pseudo-random
algorithm for selecting resources of an access channel. At 916,
method 900 can initiate the algorithm and generate a subset of
selected resources. At 918, method 900 can obtain the resources,
and broadcast the resources at 932.
[0093] At 920, method 900 can select a planned re-use algorithm
based on high interference. AT 922, method 900 can initiate
negotiations with a neighboring or interfering base station.
Negotiations can be conducted over a backhaul network (e.g. wired
or wireless connection) or can be conducted over-the-air via an
access terminal. Additionally, negotiations can be governed by
planned re-use rules, giving resource priority based on QoS
commitments, network load, or a combination thereof. Based on
relative priority of a set of access points, subsets of resources
are allocated to respective base stations at 924. Respective
resources are transmitted by respective base stations at 932.
[0094] For static resource provisioning, method 900 proceeds from
904 to 926. At 926, method 900 can determine whether type-based
provisioning is employed. If so, method 900 proceeds to 930 where
resources are selected based on transmit power, association type or
like category of base station. If no type provisioning is employed
by the network, a default set of resources are selected at 928.
Method 900 can proceed for 928 or 930 to 932, and broadcast the
respective resources.
[0095] FIG. 10 depicts a flowchart of an example methodology 1000
according to further aspects of the subject disclosure. At 1002,
method 1000 can employ a receiver to obtain a set of wireless
signal access resources employed by a network access point. At
1004, method 1000 can employ a data processor to select a subset of
the resources to transmit an access probe to a wireless network.
Additionally, the access probe can include a set of DL resources
reserved for the network access point, by a neighboring or
interfering access point. At 1006, method 1000 can employ a
transmitter to deliver the access probe and DL resources to the
network access point.
[0096] FIG. 11 illustrates a flowchart of a sample methodology 1100
for adaptive access to a wireless network. At 1102, method 1100 can
obtain access point pilot transmissions of a set of network access
points. At 1104, method 1100 can identify a preferred access point.
At 1106, method 1100 can measure interference of the non-preferred
access point signals with respect to the preferred access point
signal. At 1108, method 1100 can optionally request reduced
interference from non-preferred access points. The request can be
based on a minimum measured interference from such non-preferred
access points, for instance. Additionally, at 1110, method 1100 can
optionally forward specified DL resources reserved for the
preferred network access point, if any.
[0097] At 1112, method 1100 can obtain a select set of access
resources for submitting an access request to the preferred network
access point. According to some aspects of the subject disclosure,
the set can be obtained from the preferred network access point, or
broadcast from a neighboring access point. In other aspects of the
subject disclosure, the set of access resources can be generated at
an access terminal, based on network load data transmitted by one
or more network access points, or estimated interference based on
interference measurements at the access terminal.
[0098] At 1114, method 1100 can submit an access probe to the
preferred access point, utilizing the select set of access
resources. Optionally, the access probe can include reserved DL
resources, as specified above. AT 1116, method 1100 can monitor DL
resources for a response to the access probe. Optionally, the
monitored DL resources can comprise any reserved DL resources
specified in the access probe.
[0099] FIGS. 12 and 13 illustrate example systems 1200, 1300 for
implementing re-use in wireless access communications and providing
coordinated resource reservation, respectively, according to
aspects of the subject disclosure. For example, systems 1200 and
1300 can reside at least partially within a wireless communication
network and/or within a transmitter such as a node, base station,
access point, user terminal, personal computer coupled with a
mobile interface card, or the like. It is to be appreciated that
systems 1200 and 1300 are represented as including functional
blocks, which can be functional blocks that represent functions
implemented by a processor, software, or combination thereof (e.g.
firmware).
[0100] System 1200 comprises a module 1202 for obtaining network
access resources from a network access point. The network access
resources can comprise a general use channel for access probes
within a wireless environment. Additionally, system 1200 can
comprise a module 1204 for modifying the resources based on network
load or network interference conditions. Modification can be based
on an executed re-use algorithm that selects a subset of UL access
channel resources for a particular network access point.
Additionally, system 1200 can comprise a module for broadcasting
the modified resources to access terminals in a wireless coverage
area served by system 1200.
[0101] System 1300 can comprise a module 1302 for receiving UL
access resources from a wireless network access point. Furthermore,
system 1300 can comprise a module for negotiating reserved DL
access resources from an access point neighboring or interfering
with the network access point. Further to the above, system 1300
can comprise a module 1306 for including the reserved DL access
resources in an access probe, and deliver the access probe to the
wireless network access point on the received UL access
resources.
[0102] FIG. 14 depicts a block diagram of an example system 1400
that can facilitate wireless communication according to some
aspects disclosed herein. On a downlink, at access point 1405, a
transmit (TX) data processor 1410 receives, formats, codes,
interleaves, and modulates (or symbol maps) traffic data and
provides modulation symbols ("data symbols"). A symbol modulator
1415 receives and processes the data symbols and pilot symbols and
provides a stream of symbols. A symbol modulator 1420 multiplexes
data and pilot symbols and provides them to a transmitter unit
(TMTR) 1420. Each transmit symbol can be a data symbol, a pilot
symbol, or a signal value of zero. The pilot symbols can be sent
continuously in each symbol period. The pilot symbols can be
frequency division multiplexed (FDM), orthogonal frequency division
multiplexed (OFDM), time division multiplexed (TDM), code division
multiplexed (CDM), or a suitable combination thereof or of like
modulation and/or transmission techniques.
[0103] TMTR 1420 receives and converts the stream of symbols into
one or more analog signals and further conditions (e.g. amplifies,
filters, and frequency upconverts) the analog signals to generate a
downlink signal suitable for transmission over the wireless
channel. The downlink signal is then transmitted through an antenna
1425 to the terminals. At terminal 1430, an antenna 1435 receives
the downlink signal and provides a received signal to a receiver
unit (RCVR) 1440. Receiver unit 1440 conditions (e.g., filters,
amplifies, and frequency downconverts) the received signal and
digitizes the conditioned signal to obtain samples. A symbol
demodulator 1445 demodulates and provides received pilot symbols to
a processor 1450 for channel estimation. Symbol demodulator 1445
further receives a frequency response estimate for the downlink
from processor 1450, performs data demodulation on the received
data symbols to obtain data symbol estimates (which are estimates
of the transmitted data symbols), and provides the data symbol
estimates to an RX data processor 1455, which demodulates (i.e.,
symbol demaps), deinterleaves, and decodes the data symbol
estimates to recover the transmitted traffic data. The processing
by symbol demodulator 1445 and RX data processor 1455 is
complementary to the processing by symbol modulator 1415 and TX
data processor 1410, respectively, at access point 1405.
[0104] On the uplink, a TX data processor 1460 processes traffic
data and provides data symbols. A symbol modulator 1465 receives
and multiplexes the data symbols with pilot symbols, performs
modulation, and provides a stream of symbols. A transmitter unit
1470 then receives and processes the stream of symbols to generate
an uplink signal, which is transmitted by the antenna 1435 to the
access point 1405. Specifically, the uplink signal can be in
accordance with SC-FDMA requirements and can include frequency
hopping mechanisms as described herein.
[0105] At access point 1405, the uplink signal from terminal 1430
is received by the antenna 1425 and processed by a receiver unit
1475 to obtain samples. A symbol demodulator 1480 then processes
the samples and provides received pilot symbols and data symbol
estimates for the uplink. An RX data processor 1485 processes the
data symbol estimates to recover the traffic data transmitted by
terminal 1430. A processor 1490 performs channel estimation for
each active terminal transmitting on the uplink. Multiple terminals
can transmit pilot concurrently on the uplink on their respective
assigned sets of pilot sub-bands, where the pilot sub-band sets can
be interlaced.
[0106] Processors 1490 and 1450 direct (e.g., control, coordinate,
manage, etc.) operation at access point 1405 and terminal 1430,
respectively. Respective processors 1490 and 1450 can be associated
with memory units (not shown) that store program codes and data.
Processors 1490 and 1450 can also perform computations to derive
frequency and impulse response estimates for the uplink and
downlink, respectively.
[0107] For a multiple-access system (e.g., SC-FDMA, FDMA, OFDMA,
CDMA, TDMA, etc.), multiple terminals can transmit concurrently on
the uplink. For such a system, the pilot sub-bands can be shared
among different terminals. The channel estimation techniques can be
used in cases where the pilot sub-bands for each terminal span the
entire operating band (possibly except for the band edges). Such a
pilot sub-band structure would be desirable to obtain frequency
diversity for each terminal. The techniques described herein can be
implemented by various means. For example, these techniques can be
implemented in hardware, software, or a combination thereof. For a
hardware implementation, which can be digital, analog, or both
digital and analog, the processing units used for channel
estimation can be implemented within one or more application
specific integrated circuits (ASICs), digital signal processors
(DSPs), digital signal processing devices (DSPDs), programmable
logic devices (PLDs), field programmable gate arrays (FPGAs),
processors, controllers, micro-controllers, microprocessors, other
electronic units designed to perform the functions described
herein, or a combination thereof. With software, implementation can
be through modules (e.g., procedures, functions, and so on) that
perform the functions described herein. The software codes can be
stored in memory unit and executed by the processors 1490 and
1450.
[0108] FIG. 15 illustrates a wireless communication system 1500
with multiple base stations (BSs) 1510 (e.g., wireless access
points, wireless communication apparatus) and multiple terminals
1520 (e.g., ATs), such as can be utilized in conjunction with one
or more aspects. A BS (1510) is generally a fixed station that
communicates with the terminals and can also be called an access
point, a Node B, or some other terminology. Each BS 1510 provides
communication coverage for a particular geographic area or coverage
area, illustrated as three geographic areas in FIG. 15, labeled
1502a, 1502b, and 1502c. The term "cell" can refer to a BS or its
coverage area depending on the context in which the term is used.
To improve system capacity, a BS geographic area/coverage area can
be partitioned into multiple smaller areas (e.g., three smaller
areas, according to cell 1502a in FIG. 15), 1504a, 1504b, and
1504c. Each smaller area (1504a, 1504b, 1504c) can be served by a
respective base transceiver subsystem (BTS). The term "sector" can
refer to a BTS or its coverage area depending on the context in
which the term is used. For a sectorized cell, the BTSs for all
sectors of that cell are typically co-located within the base
station for the cell. The transmission techniques described herein
can be used for a system with sectorized cells as well as a system
with un-sectorized cells. For simplicity, in the subject
description, unless specified otherwise, the term "base station" is
used generically for a fixed station that serves a sector as well
as a fixed station that serves a cell.
[0109] Terminals 1520 are typically dispersed throughout the
system, and each terminal 1520 can be fixed or mobile. Terminals
1520 can also be called a mobile station, user equipment, a user
device, wireless communication apparatus, an access terminal, a
user terminal or some other terminology. A terminal 1520 can be a
wireless device, a cellular phone, a personal digital assistant
(PDA), a wireless modem card, and so on. Each terminal 1520 can
communicate with zero, one, or multiple BSs 1510 on the downlink
(e.g., FL) and uplink (e.g., RL) at any given moment. The downlink
refers to the communication link from the base stations to the
terminals, and the uplink refers to the communication link from the
terminals to the base stations.
[0110] For a centralized architecture, a system controller 1530
couples to base stations 1510 and provides coordination and control
for BSs 1510. For a distributed architecture, BSs 1510 can
communicate with one another as needed (e.g., by way of a wired or
wireless backhaul network communicatively coupling the BSs 1510).
Data transmission on the forward link often occurs from one access
point to one access terminal at or near the maximum data rate that
can be supported by the forward link or the communication system.
Additional channels of the forward link (e.g. control channel) can
be transmitted from multiple access points to one access terminal.
Reverse link data communication can occur from one access terminal
to one or more access points.
[0111] FIG. 16 illustrates an exemplary communication system
enabling deployment of HNB base stations (Femto base stations)
within a network environment. As shown in FIG. 16, the system 1600
includes multiple HNB units 1610. HNBs 1610 are each installed in a
corresponding small area network environment 1630, e.g., a user
residence or other user-controlled environment such as a small or
home office. Further HNBs 1610 are configured to serve associated
user equipment (UE) 1620. In some embodiments HNBs are further
configured to serve alien UE. Each HNB 1610 is coupled to a public
network 1640 and a mobile operator core network 1650 via a network
link (not shown). Preferably the public network 1640 is the
Internet. Exemplary network links include cable modems or DSL
routers.
[0112] Although embodiments described herein use 3GPP terminology,
one skilled in the art should understand that the embodiments may
be applied to 3GPP2 technology (1.times.RTT, 1.times.EVDO Rl0,
RevA, RevB) as well as 3GPP technology (Rel99, Rel5, Rel6, Rel7)
and other related technologies. In embodiments described herein,
preferably the owner of the HNB 1610 subscribes to mobile service,
e.g. 3G mobile service, offered through the mobile operator core
network 1650 and the UE 1620 is capable of operating both in a
macro cellular environment and in residential small area network
environment of which HNB 1610 is part. Thus the network environment
of which HNB 1610 is part is backward compatible with existing UE
1620.
[0113] As used in the subject disclosure, the terms "component,"
"system," "module" and the like are intended to refer to a
computer-related entity, either hardware, software, software in
execution, firmware, middle ware, microcode, and/or any combination
thereof. For example, a module can be, but is not limited to being,
a process running on a processor, a processor, an object, an
executable, a thread of execution, a program, a device, and/or a
computer. One or more modules can reside within a process, or
thread of execution; and a module can be localized on one
electronic device, or distributed between two or more electronic
devices. Further, these modules can execute from various
computer-readable media having various data structures stored
thereon. The modules can communicate by way of local or remote
processes such as in accordance with a signal having one or more
data packets (e.g. data from one component interacting with another
component in a local system, distributed system, or across a
network such as the Internet with other systems by way of the
signal). Additionally, components or modules of systems described
herein can be rearranged, or complemented by additional
components/modules/systems in order to facilitate achieving the
various aspects, goals, advantages, etc., described with regard
thereto, and are not limited to the precise configurations set
forth in a given figure, as will be appreciated by one skilled in
the art.
[0114] Furthermore, various aspects are described herein in
connection with a user equipment (UE). A UE can also be called a
system, a subscriber unit, a subscriber station, mobile station,
mobile, mobile communication device, mobile device, remote station,
remote terminal, access terminal (AT), user agent (UA), a user
device, or user terminal (UE). A subscriber station can be a
cellular telephone, a cordless telephone, a Session Initiation
Protocol (SIP) phone, a wireless local loop (WLL) station, a
personal digital assistant (PDA), a handheld device having wireless
connection capability, or other processing device connected to a
wireless modem or similar mechanism facilitating wireless
communication with a processing device.
[0115] In one or more exemplary embodiments, the functions
described can be implemented in hardware, software, firmware,
middleware, microcode, or any suitable combination thereof If
implemented in software, the functions can be stored on or
transmitted over as one or more instructions or code on a
computer-readable medium. Computer-readable media includes both
computer storage media and communication media including any medium
that facilitates transfer of a computer program from one place to
another. A storage media may be any physical media that can be
accessed by a computer. By way of example, and not limitation, such
computer storage media can comprise RAM, ROM, EEPROM, CD-ROM or
other optical disk storage, magnetic disk storage or other magnetic
storage devices, smart cards, and flash memory devices (e.g., card,
stick, key drive . . . ), or any other medium that can be used to
carry or store desired program code in the form of instructions or
data structures and that can be accessed by a computer. For
example, if the software is transmitted from a website, server, or
other remote source using a coaxial cable, fiber optic cable,
twisted pair, digital subscriber line (DSL), or wireless
technologies such as infrared, radio, and microwave, then the
coaxial cable, fiber optic cable, twisted pair, DSL, or wireless
technologies such as infrared, radio, and microwave are included in
the definition of medium. Disk and disc, as used herein, includes
compact disc (CD), laser disc, optical disc, digital versatile disc
(DVD), floppy disk and blu-ray disc where disks usually reproduce
data magnetically, while discs reproduce data optically with
lasers. Combinations of the above should also be included within
the scope of computer-readable media.
[0116] For a hardware implementation, the processing units' various
illustrative logics, logical blocks, modules, and circuits
described in connection with the aspects disclosed herein can be
implemented or performed within one or more ASICs, DSPs, DSPDs,
PLDs, FPGAs, discrete gate or transistor logic, discrete hardware
components, general purpose processors, controllers,
micro-controllers, microprocessors, other electronic units designed
to perform the functions described herein, or a combination
thereof. A general-purpose processor can be a microprocessor, but,
in the alternative, the processor can be any conventional
processor, controller, microcontroller, or state machine. A
processor can also be implemented as a combination of computing
devices, e.g. a combination of a DSP and a microprocessor, a
plurality of microprocessors, one or more microprocessors in
conjunction with a DSP core, or any other suitable configuration.
Additionally, at least one processor can comprise one or more
modules operable to perform one or more of the steps and/or actions
described herein.
[0117] Moreover, various aspects or features described herein can
be implemented as a method, apparatus, or article of manufacture
using standard programming and/or engineering techniques. Further,
the steps and/or actions of a method or algorithm described in
connection with the aspects disclosed herein can be embodied
directly in hardware, in a software module executed by a processor,
or in a combination of the two. Additionally, in some aspects, the
steps or actions of a method or algorithm can reside as at least
one or any combination or set of codes or instructions on a
machine-readable medium, or computer-readable medium, which can be
incorporated into a computer program product. The term "article of
manufacture" as used herein is intended to encompass a computer
program accessible from any suitable computer-readable device or
media.
[0118] Additionally, the word "exemplary" is used herein to mean
serving as an example, instance, or illustration. Any aspect or
design described herein as "exemplary" is not necessarily to be
construed as preferred or advantageous over other aspects or
designs. Rather, use of the word exemplary is intended to present
concepts in a concrete fashion. As used in this application, the
term "or" is intended to mean an inclusive "or" rather than an
exclusive "or". That is, unless specified otherwise, or clear from
context, "X employs A or B" is intended to mean any of the natural
inclusive permutations. That is, if X employs A; X employs B; or X
employs both A and B, then "X employs A or B" is satisfied under
any of the foregoing instances. In addition, the articles "a" and
"an" as used in this application and the appended claims should
generally be construed to mean "one or more" unless specified
otherwise or clear from context to be directed to a singular
form.
[0119] Furthermore, as used herein, the terms to "infer" or
"inference" refer generally to the process of reasoning about or
inferring states of the system, environment, or user from a set of
observations as captured via events, or data. Inference can be
employed to identify a specific context or action, or can generate
a probability distribution over states, for example. The inference
can be probabilistic-that is, the computation of a probability
distribution over states of interest based on a consideration of
data and events. Inference can also refer to techniques employed
for composing higher-level events from a set of events, or data.
Such inference results in the construction of new events or actions
from a set of observed events and/or stored event data, whether or
not the events are correlated in close temporal proximity, and
whether the events and data come from one or several event and data
sources.
[0120] What has been described above includes examples of aspects
of the claimed subject matter. It is, of course, not possible to
describe every conceivable combination of components or
methodologies for purposes of describing the claimed subject
matter, but one of ordinary skill in the art may recognize that
many further combinations and permutations of the disclosed subject
matter are possible. Accordingly, the disclosed subject matter is
intended to embrace all such alterations, modifications and
variations that fall within the spirit and scope of the appended
claims. Furthermore, to the extent that the terms "includes," "has"
or "having" are used in either the detailed description or the
claims, such terms are intended to be inclusive in a manner similar
to the term "comprising" as "comprising" is interpreted when
employed as a transitional word in a claim.
* * * * *